Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States.
Inorg Chem. 2011 Oct 3;50(19):9696-704. doi: 10.1021/ic2014946. Epub 2011 Sep 8.
Three polynuclear thorium(IV) molecular complexes have been synthesized under ambient conditions from reactions of an amorphous Th precipitate, obtained via hydrolysis, with carboxylate functionalized ligands. The structures of Th(6)(OH)(4)O(4)(H(2)O)(6)(HCO(2))(12)·nH(2)O (1), Th(6)(OH)(4)O(4)(H(2)O)(6)(CH(3)CO(2))(12)·nH(2)O (2), Th(6)(OH)(4)O(4)(H(2)O)(6)(ClCH(2)CO(2))(12)·4H(2)O (3) each consist of a hexanuclear Th core wherein six 9-coordinate Th(IV) cations are bridged by four μ(3)-hydroxo and four μ(3)-oxo groups. Each Th(IV) center is additionally coordinated to one bound "apical" water molecule and four oxygen atoms from bridging carboxylate functionalized organic acid units. "Decoration" of the cationic Th(6)(μ(3)-O)(4)(μ(3)-OH)(4) cores by anionic shells of R-COO(-) ligands (R = H, CH(3), or CH(2)Cl) terminates the oligomers and results in the formation of discrete, neutral molecular clusters. Electronic structure calculations at the density functional theory level predicted that the most energetically favorable positions for the protons on the hexanuclear core result in the cluster with the highest symmetry with the protons separated as much as possible. The synthesis, structure, and characterization of the materials are reported.
三种多核钍（IV）分子配合物在环境条件下通过水解得到的无定形 Th 沉淀物与羧酸官能化配体反应合成。Th(6)(OH)(4)O(4)(H(2)O)(6)(HCO(2))(12)·nH(2)O (1)、Th(6)(OH)(4)O(4)(H(2)O)(6)(CH(3)CO(2))(12)·nH(2)O (2)和 Th(6)(OH)(4)O(4)(H(2)O)(6)(ClCH(2)CO(2))(12)·4H(2)O (3)的结构均由六核 Th 核组成，其中六个 9 配位 Th(IV)阳离子通过四个 μ(3)-羟基和四个 μ(3)-氧桥连接。每个 Th(IV)中心另外与一个配位的“顶点”水分子和来自桥接羧酸官能化有机酸单元的四个氧原子配位。由阴离子 R-COO(-)配体（R = H、CH(3)或 CH(2)Cl）外壳“装饰”阳离子Th(6)(μ(3)-O)(4)(μ(3)-OH)(4)核终止了低聚物的形成，并导致离散的中性分子簇的形成。密度泛函理论水平的电子结构计算预测，六核核中质子最有利的能量位置导致具有最高对称性的簇，质子尽可能分开。报道了材料的合成、结构和表征。
